\Em`py*e"ma\, n. [NL., fr. Gr. ?, from ? to suppurate; ?
in + ? pus.] (Med.)
A collection of blood, pus, or other fluid, in some cavity of
the body, especially that of the pleura. --Dunglison.

Note: The term empyema is now restricted to a collection of
      pus in the cavity of the pleura.